HORIZON vs VENUS: which needs more amplifier?

The Moondrop HORIZON is 32Ω at 94.1 dB/mW; the Moondrop VENUS is 18Ω at 82.6 dB/mW. This page is only about what they ask of an amplifier — not how they sound, which no specification on either sheet can tell you.

The VENUS needs 11.5 dB more than the HORIZON to reach the same loudness — 55 mW against 3.9 mW.

The numbers that decide it

SpecificationHORIZONVENUS
Impedance32 Ω18 Ω
Sensitivity94.1 dB/mW82.6 dB/mW
Sensitivity (voltage)109.0 dB/V100.0 dB/V
Power for 100 dB3.9 mW55 mW
Voltage for 100 dB0.35 V0.99 V
Current for 100 dB11.0 mA55.3 mA
Highest source impedance
that leaves them alone (one-eighth rule)
4.00 Ω2.25 Ω
Sources that reach 100 dB
out of 280
280225

Where the two part company

55 of the 280 sources have the power for the HORIZON but not for the VENUS — Apple USB-C dongle (US), Apple USB-C dongle (EU), Generic CX31993 dongles, 52 more.

225 of the 280 sources here reach 100 dB on both. That count is about power only — the output-impedance and hiss lines above are separate questions, and a source can pass this one and fail those.

Both pages in full

Each model has a page of its own with the full source list, the hiss estimate and the provenance of every figure above: Moondrop HORIZON and Moondrop VENUS. Every figure on this page comes from what Moondrop published, or is derived from it — what that maker publishes, counted.